June 29, 2011 (San Diego) -- Most people with diabetes know the lifestyle changes they need to make to help control their condition but fail to follow through, according to findings of the largest nongovernmental study of its kind.

Nearly nine out of 10 (87%) of 3,867 people with type 2 diabetes surveyed knew that obesity can aggravate their disease. But only 70% said they had tried to lose weight in the previous year. And only one in three indicated they had maintained their desired weight for more than six months.

About one in five participants (17%) reported they prefer a pill to exercise and diet, and 5% said they didn't even bother to try and stay healthy, says Andrew Green, MD, director of Midwestern Endocrinology in Overland Park, Kan.

When it came to exercise, 63% of respondents reported their doctor had recommended an increase in physical activity in the past 12 months. But only 13% said they were physically active within the last week.

"We thought that if people knew something caused adverse effects, they would change their behavior. But it turns out that is not true," Green tells WebMD.

Participants filled out eight-page questionnaires on their health and lifestyles.

Green presented results of the SHIELD (The Study to Help Improve Early Evaluation and Management of Risk Factors Leading to Diabetes) study at the annual meeting of the American Diabetes Association here.

Motivating People With Diabetes

The survey also showed that access to health care is not the problem, Green says. More than 80% of participants went to the doctor at least three times a year.

So if knowledge is not power, what should be done?

James R Gavin III, MD, PhD, clinical professor of medicine at Emory University School of Medicine in Atlanta, says, "SHIELD confirmed it is time we move well beyond awareness."

"The results contradict the widely held notion that [diabetes patients] who are well informed about their disease and have good access to health care are likely to favorably alter their lifestyles per their doctors' recommendations," says Gavin, who is also chair of the Partnership for a Healthier America, an initiative to fight childhood obesity.

What is needed, Green says, are new ways to motivate patients. That could include a tax on sugary drinks, more nutritious school lunches, and even insurance discounts for patients who improve their health, he says.

Risk Factors for Diabetes

Another part of the SHIELD study examined the risk factors for diabetes among more than 10,000 people who did not have the condition when originally surveyed.

Over a five-year period:

Increasing age was the strongest predictor, with the oldest people studied being four to six times more likely to develop type 2 diabetes than the youngest people, says Helena Rodbard, MD, director of Endocrine and Metabolic Consultants in Rockville, Md.

High blood sugar was associated with a fivefold increased risk of receiving a diabetes diagnosis.

Obesity doubled the risk.

A family history of type 2 diabetes increased risk by 50%.

The study was sponsored by AstraZeneca.

These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.